This project will isolate and characterize T-cell products which may be involved in antigen recognition. T cell proteins which bind antigen will be isolated from specifically sensitized T cells by absorbtion to and elution from antigen immunoabsorbents. Isolated antigen-binding molecules will be characterized by polyacrylamide gel electorphoresis, isoelectric focussing and peptide mapping. The expression of these molecules by T cell subsets will be determined. Antisera to antigen-binding T cell proteins will be prepared to study the function of these molecules in antigen recognition.